/**
* @license Highcharts JS v6.0.1 (2017-10-05)
* Accessibility module
*
* (c) 2010-2017 Highsoft AS
* Author: Oystein Moseng
*
* License: www.highcharts.com/license
*/
'use strict';
(function(factory) {
if (typeof module === 'object' && module.exports) {
module.exports = factory;
} else {
factory(Highcharts);
}
}(function(Highcharts) {
(function(H) {
/**
* Accessibility module
*
* (c) 2010-2017 Highsoft AS
* Author: Oystein Moseng
*
* License: www.highcharts.com/license
*/
/* eslint max-len: ["warn", 80, 4] */
var win = H.win,
doc = win.document,
each = H.each,
erase = H.erase,
addEvent = H.addEvent,
removeEvent = H.removeEvent,
fireEvent = H.fireEvent,
dateFormat = H.dateFormat,
merge = H.merge,
// CSS style to hide element from visual users while still exposing it to
// screen readers
hiddenStyle = {
position: 'absolute',
left: '-9999px',
top: 'auto',
width: '1px',
height: '1px',
overflow: 'hidden'
},
// Human readable description of series and each point in singular and
// plural
typeToSeriesMap = {
'default': ['series', 'data point', 'data points'],
'line': ['line', 'data point', 'data points'],
'spline': ['line', 'data point', 'data points'],
'area': ['line', 'data point', 'data points'],
'areaspline': ['line', 'data point', 'data points'],
'pie': ['pie', 'slice', 'slices'],
'column': ['column series', 'column', 'columns'],
'bar': ['bar series', 'bar', 'bars'],
'scatter': ['scatter series', 'data point', 'data points'],
'boxplot': ['boxplot series', 'box', 'boxes'],
'arearange': ['arearange series', 'data point', 'data points'],
'areasplinerange': [
'areasplinerange series',
'data point',
'data points'
],
'bubble': ['bubble series', 'bubble', 'bubbles'],
'columnrange': ['columnrange series', 'column', 'columns'],
'errorbar': ['errorbar series', 'errorbar', 'errorbars'],
'funnel': ['funnel', 'data point', 'data points'],
'pyramid': ['pyramid', 'data point', 'data points'],
'waterfall': ['waterfall series', 'column', 'columns'],
'map': ['map', 'area', 'areas'],
'mapline': ['line', 'data point', 'data points'],
'mappoint': ['point series', 'data point', 'data points'],
'mapbubble': ['bubble series', 'bubble', 'bubbles']
},
// Descriptions for exotic chart types
typeDescriptionMap = {
boxplot: ' Box plot charts are typically used to display groups of ' +
'statistical data. Each data point in the chart can have up to 5 ' +
'values: minimum, lower quartile, median, upper quartile and ' +
'maximum. ',
arearange: ' Arearange charts are line charts displaying a range ' +
'between a lower and higher value for each point. ',
areasplinerange: ' These charts are line charts displaying a range ' +
'between a lower and higher value for each point. ',
bubble: ' Bubble charts are scatter charts where each data point ' +
'also has a size value. ',
columnrange: ' Columnrange charts are column charts displaying a ' +
'range between a lower and higher value for each point. ',
errorbar: ' Errorbar series are used to display the variability of ' +
'the data. ',
funnel: ' Funnel charts are used to display reduction of data in ' +
'stages. ',
pyramid: ' Pyramid charts consist of a single pyramid with item ' +
'heights corresponding to each point value. ',
waterfall: ' A waterfall chart is a column chart where each column ' +
'contributes towards a total end value. '
};
// If a point has one of the special keys defined, we expose all keys to the
// screen reader.
H.Series.prototype.commonKeys = ['name', 'id', 'category', 'x', 'value', 'y'];
H.Series.prototype.specialKeys = [
'z', 'open', 'high', 'q3', 'median', 'q1', 'low', 'close'
];
// A pie is always simple. Don't quote me on that.
if (H.seriesTypes.pie) {
H.seriesTypes.pie.prototype.specialKeys = [];
}
// Set for which series types it makes sense to move to the closest point with
// up/down arrows, and which series types should just move to next series.
H.Series.prototype.keyboardMoveVertical = true;
each(['column', 'pie'], function(type) {
if (H.seriesTypes[type]) {
H.seriesTypes[type].prototype.keyboardMoveVertical = false;
}
});
/**
* Accessibility options
* @type {Object}
* @optionparent
*/
H.setOptions({
/**
* Options for configuring accessibility for the chart. Requires the
* [accessibility module](//code.highcharts.com/modules/accessibility.
* js) to be loaded. For a description of the module and information
* on its features, see [Highcharts Accessibility](http://www.highcharts.
* com/docs/chart-concepts/accessibility).
*
* @since 5.0.0
*/
accessibility: {
/**
* Enable accessibility features for the chart.
*
* @type {Boolean}
* @default true
* @since 5.0.0
*/
enabled: true,
/**
* When a series contains more points than this, we no longer expose
* information about individual points to screen readers.
*
* Set to `false` to disable.
*
* @type {Number|Boolean}
* @default 30
* @since 5.0.0
*/
pointDescriptionThreshold: 30, // set to false to disable
/**
* Options for keyboard navigation.
*
* @type {Object}
* @since 5.0.0
*/
keyboardNavigation: {
/**
* Enable keyboard navigation for the chart.
*
* @type {Boolean}
* @default true
* @since 5.0.0
*/
enabled: true
/**
* Skip null points when navigating through points with the
* keyboard.
*
* @type {Boolean}
* @default false
* @since 5.0.0
* @apioption accessibility.keyboardNavigation.skipNullPoints
*/
}
/**
* Whether or not to add series descriptions to charts with a single
* series.
*
* @type {Boolean}
* @default false
* @since 5.0.0
* @apioption accessibility.describeSingleSeries
*/
/**
* Function to run upon clicking the "View as Data Table" link in the
* screen reader region.
*
* By default Highcharts will insert and set focus to a data table
* representation of the chart.
*
* @type {Function}
* @since 5.0.0
* @apioption accessibility.onTableAnchorClick
*/
/**
* Date format to use for points on datetime axes when describing them
* to screen reader users.
*
* Defaults to the same format as in tooltip.
*
* For an overview of the replacement codes, see
* [dateFormat](#Highcharts.dateFormat).
*
* @type {String}
* @see [pointDateFormatter](#accessibility.pointDateFormatter)
* @since 5.0.0
* @apioption accessibility.pointDateFormat
*/
/**
* Formatter function to determine the date/time format used with
* points on datetime axes when describing them to screen reader users.
* Receives one argument, `point`, referring to the point to describe.
* Should return a date format string compatible with
* [dateFormat](#Highcharts.dateFormat).
*
* @type {Function}
* @see [pointDateFormat](#accessibility.pointDateFormat)
* @since 5.0.0
* @apioption accessibility.pointDateFormatter
*/
/**
* Formatter function to use instead of the default for point
* descriptions.
* Receives one argument, `point`, referring to the point to describe.
* Should return a String with the description of the point for a screen
* reader user.
*
* @type {Function}
* @see [point.description](#series.line.data.description)
* @since 5.0.0
* @apioption accessibility.pointDescriptionFormatter
*/
/**
* A formatter function to create the HTML contents of the hidden screen
* reader information region. Receives one argument, `chart`, referring
* to the chart object. Should return a String with the HTML content
* of the region.
*
* The link to view the chart as a data table will be added
* automatically after the custom HTML content.
*
* @type {Function}
* @default undefined
* @since 5.0.0
* @apioption accessibility.screenReaderSectionFormatter
*/
/**
* Formatter function to use instead of the default for series
* descriptions. Receives one argument, `series`, referring to the
* series to describe. Should return a String with the description of
* the series for a screen reader user.
*
* @type {Function}
* @see [series.description](#plotOptions.series.description)
* @since 5.0.0
* @apioption accessibility.seriesDescriptionFormatter
*/
}
});
/**
* A text description of the chart.
*
* If the Accessibility module is loaded, this is included by default
* as a long description of the chart and its contents in the hidden
* screen reader information region.
*
* @type {String}
* @see [typeDescription](#chart.typeDescription)
* @default undefined
* @since 5.0.0
* @apioption chart.description
*/
/**
* A text description of the chart type.
*
* If the Accessibility module is loaded, this will be included in the
* description of the chart in the screen reader information region.
*
*
* Highcharts will by default attempt to guess the chart type, but for
* more complex charts it is recommended to specify this property for
* clarity.
*
* @type {String}
* @default undefined
* @since 5.0.0
* @apioption chart.typeDescription
*/
/**
* Keyboard navigation for the legend. Requires the Accessibility module.
* @since 5.0.14
* @apioption legend.keyboardNavigation
*/
/**
* Enable/disable keyboard navigation for the legend. Requires the Accessibility
* module.
*
* @type {Boolean}
* @see [accessibility.keyboardNavigation](#accessibility.keyboardNavigation.
* enabled)
* @default true
* @since 5.0.13
* @apioption legend.keyboardNavigation.enabled
*/
/**
* HTML encode some characters vulnerable for XSS.
* @param {string} html The input string
* @return {string} The excaped string
*/
function htmlencode(html) {
return html
.replace(/&/g, '&')
.replace(//g, '>')
.replace(/"/g, '"')
.replace(/'/g, ''')
.replace(/\//g, '/');
}
// Utility function. Reverses child nodes of a DOM element
function reverseChildNodes(node) {
var i = node.childNodes.length;
while (i--) {
node.appendChild(node.childNodes[i]);
}
}
// Utility function to attempt to fake a click event on an element
function fakeClickEvent(element) {
var fakeEvent;
if (element && element.onclick && doc.createEvent) {
fakeEvent = doc.createEvent('Events');
fakeEvent.initEvent('click', true, false);
element.onclick(fakeEvent);
}
}
// Determine if a point should be skipped
function isSkipPoint(point) {
return point.isNull &&
point.series.chart.options.accessibility
.keyboardNavigation.skipNullPoints ||
point.series.options.skipKeyboardNavigation ||
!point.series.visible;
}
// Get the point in a series that is closest to a reference point
// Optionally supply weight factors for x and y directions
function getClosestPoint(point, series, xWeight, yWeight) {
var minDistance = Infinity,
dPoint,
minIx,
distance,
i = series.points.length;
if (point.plotX === undefined || point.plotY === undefined) {
return;
}
while (i--) {
dPoint = series.points[i];
if (dPoint.plotX === undefined || dPoint.plotY === undefined) {
return;
}
distance = (point.plotX - dPoint.plotX) *
(point.plotX - dPoint.plotX) * (xWeight || 1) +
(point.plotY - dPoint.plotY) *
(point.plotY - dPoint.plotY) * (yWeight || 1);
if (distance < minDistance) {
minDistance = distance;
minIx = i;
}
}
return series.points[minIx || 0];
}
// Whenever drawing series, put info on DOM elements
H.wrap(H.Series.prototype, 'render', function(proceed) {
proceed.apply(this, Array.prototype.slice.call(arguments, 1));
if (this.chart.options.accessibility.enabled) {
this.setA11yDescription();
}
});
// Put accessible info on series and points of a series
H.Series.prototype.setA11yDescription = function() {
var a11yOptions = this.chart.options.accessibility,
firstPointEl = (
this.points &&
this.points.length &&
this.points[0].graphic &&
this.points[0].graphic.element
),
seriesEl = (
firstPointEl &&
firstPointEl.parentNode || this.graph &&
this.graph.element || this.group &&
this.group.element
); // Could be tracker series depending on series type
if (seriesEl) {
// For some series types the order of elements do not match the order of
// points in series. In that case we have to reverse them in order for
// AT to read them out in an understandable order
if (seriesEl.lastChild === firstPointEl) {
reverseChildNodes(seriesEl);
}
// Make individual point elements accessible if possible. Note: If
// markers are disabled there might not be any elements there to make
// accessible.
if (
this.points && (
this.points.length < a11yOptions.pointDescriptionThreshold ||
a11yOptions.pointDescriptionThreshold === false
)
) {
each(this.points, function(point) {
if (point.graphic) {
point.graphic.element.setAttribute('role', 'img');
point.graphic.element.setAttribute('tabindex', '-1');
point.graphic.element.setAttribute('aria-label',
point.series.options.pointDescriptionFormatter &&
point.series.options.pointDescriptionFormatter(point) ||
a11yOptions.pointDescriptionFormatter &&
a11yOptions.pointDescriptionFormatter(point) ||
point.buildPointInfoString());
}
});
}
// Make series element accessible
if (this.chart.series.length > 1 || a11yOptions.describeSingleSeries) {
seriesEl.setAttribute(
'role',
this.options.exposeElementToA11y ? 'img' : 'region'
);
seriesEl.setAttribute('tabindex', '-1');
seriesEl.setAttribute(
'aria-label',
a11yOptions.seriesDescriptionFormatter &&
a11yOptions.seriesDescriptionFormatter(this) ||
this.buildSeriesInfoString()
);
}
}
};
// Return string with information about series
H.Series.prototype.buildSeriesInfoString = function() {
var typeInfo = (
typeToSeriesMap[this.type] ||
typeToSeriesMap['default'] // eslint-disable-line dot-notation
),
description = this.description || this.options.description;
return (this.name ? this.name + ', ' : '') +
(this.chart.types.length === 1 ? typeInfo[0] : 'series') +
' ' + (this.index + 1) + ' of ' + (this.chart.series.length) +
(
this.chart.types.length === 1 ?
' with ' :
'. ' + typeInfo[0] + ' with '
) +
(
this.points.length + ' ' +
(this.points.length === 1 ? typeInfo[1] : typeInfo[2])
) +
(description ? '. ' + description : '') +
(
this.chart.yAxis.length > 1 && this.yAxis ?
'. Y axis, ' + this.yAxis.getDescription() :
''
) +
(
this.chart.xAxis.length > 1 && this.xAxis ?
'. X axis, ' + this.xAxis.getDescription() :
''
);
};
// Return string with information about point
H.Point.prototype.buildPointInfoString = function() {
var point = this,
series = point.series,
a11yOptions = series.chart.options.accessibility,
infoString = '',
dateTimePoint = series.xAxis && series.xAxis.isDatetimeAxis,
timeDesc =
dateTimePoint &&
dateFormat(
a11yOptions.pointDateFormatter &&
a11yOptions.pointDateFormatter(point) ||
a11yOptions.pointDateFormat ||
H.Tooltip.prototype.getXDateFormat(
point,
series.chart.options.tooltip,
series.xAxis
),
point.x
),
hasSpecialKey = H.find(series.specialKeys, function(key) {
return point[key] !== undefined;
});
// If the point has one of the less common properties defined, display all
// that are defined
if (hasSpecialKey) {
if (dateTimePoint) {
infoString = timeDesc;
}
each(series.commonKeys.concat(series.specialKeys), function(key) {
if (point[key] !== undefined && !(dateTimePoint && key === 'x')) {
infoString += (infoString ? '. ' : '') +
key + ', ' +
point[key];
}
});
} else {
// Pick and choose properties for a succint label
infoString =
(
this.name ||
timeDesc ||
this.category ||
this.id ||
'x, ' + this.x
) + ', ' +
(this.value !== undefined ? this.value : this.y);
}
return (this.index + 1) + '. ' + infoString + '.' +
(this.description ? ' ' + this.description : '');
};
// Get descriptive label for axis
H.Axis.prototype.getDescription = function() {
return (
this.userOptions && this.userOptions.description ||
this.axisTitle && this.axisTitle.textStr ||
this.options.id ||
this.categories && 'categories' ||
'values'
);
};
// Pan along axis in a direction (1 or -1), optionally with a defined
// granularity (number of steps it takes to walk across current view)
H.Axis.prototype.panStep = function(direction, granularity) {
var gran = granularity || 3,
extremes = this.getExtremes(),
step = (extremes.max - extremes.min) / gran * direction,
newMax = extremes.max + step,
newMin = extremes.min + step,
size = newMax - newMin;
if (direction < 0 && newMin < extremes.dataMin) {
newMin = extremes.dataMin;
newMax = newMin + size;
} else if (direction > 0 && newMax > extremes.dataMax) {
newMax = extremes.dataMax;
newMin = newMax - size;
}
this.setExtremes(newMin, newMax);
};
// Whenever adding or removing series, keep track of types present in chart
H.wrap(H.Series.prototype, 'init', function(proceed) {
proceed.apply(this, Array.prototype.slice.call(arguments, 1));
var chart = this.chart;
if (chart.options.accessibility.enabled) {
chart.types = chart.types || [];
// Add type to list if does not exist
if (chart.types.indexOf(this.type) < 0) {
chart.types.push(this.type);
}
addEvent(this, 'remove', function() {
var removedSeries = this,
hasType = false;
// Check if any of the other series have the same type as this one.
// Otherwise remove it from the list.
each(chart.series, function(s) {
if (
s !== removedSeries &&
chart.types.indexOf(removedSeries.type) < 0
) {
hasType = true;
}
});
if (!hasType) {
erase(chart.types, removedSeries.type);
}
});
}
});
// Return simplified description of chart type. Some types will not be familiar
// to most screen reader users, but we try.
H.Chart.prototype.getTypeDescription = function() {
var firstType = this.types && this.types[0],
mapTitle = this.series[0] && this.series[0].mapTitle;
if (!firstType) {
return 'Empty chart.';
} else if (firstType === 'map') {
return mapTitle ? 'Map of ' + mapTitle : 'Map of unspecified region.';
} else if (this.types.length > 1) {
return 'Combination chart.';
} else if (['spline', 'area', 'areaspline'].indexOf(firstType) > -1) {
return 'Line chart.';
}
return firstType + ' chart.' + (typeDescriptionMap[firstType] || '');
};
// Return object with text description of each of the chart's axes
H.Chart.prototype.getAxesDescription = function() {
var numXAxes = this.xAxis.length,
numYAxes = this.yAxis.length,
desc = {},
i;
if (numXAxes) {
desc.xAxis = 'The chart has ' + numXAxes +
(numXAxes > 1 ? ' X axes' : ' X axis') + ' displaying ';
if (numXAxes < 2) {
desc.xAxis += this.xAxis[0].getDescription() + '.';
} else {
for (i = 0; i < numXAxes - 1; ++i) {
desc.xAxis += (i ? ', ' : '') + this.xAxis[i].getDescription();
}
desc.xAxis += ' and ' + this.xAxis[i].getDescription() + '.';
}
}
if (numYAxes) {
desc.yAxis = 'The chart has ' + numYAxes +
(numYAxes > 1 ? ' Y axes' : ' Y axis') + ' displaying ';
if (numYAxes < 2) {
desc.yAxis += this.yAxis[0].getDescription() + '.';
} else {
for (i = 0; i < numYAxes - 1; ++i) {
desc.yAxis += (i ? ', ' : '') + this.yAxis[i].getDescription();
}
desc.yAxis += ' and ' + this.yAxis[i].getDescription() + '.';
}
}
return desc;
};
// Set a11y attribs on exporting menu
H.Chart.prototype.addAccessibleContextMenuAttribs = function() {
var exportList = this.exportDivElements;
if (exportList) {
// Set tabindex on the menu items to allow focusing by script
// Set role to give screen readers a chance to pick up the contents
each(exportList, function(item) {
if (item.tagName === 'DIV' &&
!(item.children && item.children.length)) {
item.setAttribute('role', 'menuitem');
item.setAttribute('tabindex', -1);
}
});
// Set accessibility properties on parent div
exportList[0].parentNode.setAttribute('role', 'menu');
exportList[0].parentNode.setAttribute('aria-label', 'Chart export');
}
};
// Highlight a point (show tooltip and display hover state). Returns the
// highlighted point.
H.Point.prototype.highlight = function() {
var chart = this.series.chart;
if (this.graphic && this.graphic.element.focus) {
this.graphic.element.focus();
}
if (!this.isNull) {
this.onMouseOver(); // Show the hover marker
// Show the tooltip
if (chart.tooltip) {
chart.tooltip.refresh(chart.tooltip.shared ? [this] : this);
}
} else {
if (chart.tooltip) {
chart.tooltip.hide(0);
}
// Don't call blur on the element, as it messes up the chart div's focus
}
chart.highlightedPoint = this;
return this;
};
// Function to highlight next/previous point in chart
// Returns highlighted point on success, false on failure (no adjacent point to
// highlight in chosen direction)
H.Chart.prototype.highlightAdjacentPoint = function(next) {
var chart = this,
series = chart.series,
curPoint = chart.highlightedPoint,
curPointIndex = curPoint && curPoint.index || 0,
curPoints = curPoint && curPoint.series.points,
lastSeries = chart.series && chart.series[chart.series.length - 1],
lastPoint = lastSeries && lastSeries.points &&
lastSeries.points[lastSeries.points.length - 1],
newSeries,
newPoint,
// Handle connecting ends - where the points array has an extra last
// point that is a reference to the first one. We skip this.
forwardSkipAmount = curPoint && curPoint.series.connectEnds &&
curPointIndex > curPoints.length - 3 ? 2 : 1;
// If no points, return false
if (!series[0] || !series[0].points) {
return false;
}
if (!curPoint) {
// No point is highlighted yet. Try first/last point depending on move
// direction
newPoint = next ? series[0].points[0] : lastPoint;
} else {
// We have a highlighted point.
// Find index of current point in series.points array. Necessary for
// dataGrouping (and maybe zoom?)
if (curPoints[curPointIndex] !== curPoint) {
for (var i = 0; i < curPoints.length; ++i) {
if (curPoints[i] === curPoint) {
curPointIndex = i;
break;
}
}
}
// Grab next/prev point & series
newSeries = series[curPoint.series.index + (next ? 1 : -1)];
newPoint = curPoints[curPointIndex + (next ? forwardSkipAmount : -1)] ||
// Done with this series, try next one
newSeries &&
newSeries.points[next ? 0 : newSeries.points.length - (
newSeries.connectEnds ? 2 : 1
)];
// If there is no adjacent point, we return false
if (newPoint === undefined) {
return false;
}
}
// Recursively skip null points or points in series that should be skipped
if (isSkipPoint(newPoint)) {
chart.highlightedPoint = newPoint;
return chart.highlightAdjacentPoint(next);
}
// There is an adjacent point, highlight it
return newPoint.highlight();
};
// Highlight first valid point in a series. Returns the point if successfully
// highlighted, otherwise false. If there is a highlighted point in the series,
// use that as starting point.
H.Series.prototype.highlightFirstValidPoint = function() {
var curPoint = this.chart.highlightedPoint,
start = curPoint.series === this ? curPoint.index : 0,
points = this.points;
for (var i = start, len = points.length; i < len; ++i) {
if (!isSkipPoint(points[i])) {
return points[i].highlight();
}
}
for (var j = start; j >= 0; --j) {
if (!isSkipPoint(points[j])) {
return points[j].highlight();
}
}
return false;
};
// Highlight next/previous series in chart. Returns false if no adjacent series
// in the direction, otherwise returns new highlighted point.
H.Chart.prototype.highlightAdjacentSeries = function(down) {
var chart = this,
newSeries,
newPoint,
adjacentNewPoint,
curPoint = chart.highlightedPoint,
lastSeries = chart.series && chart.series[chart.series.length - 1],
lastPoint = lastSeries && lastSeries.points &&
lastSeries.points[lastSeries.points.length - 1];
// If no point is highlighted, highlight the first/last point
if (!chart.highlightedPoint) {
newSeries = down ? (chart.series && chart.series[0]) : lastSeries;
newPoint = down ?
(newSeries && newSeries.points && newSeries.points[0]) : lastPoint;
return newPoint ? newPoint.highlight() : false;
}
newSeries = chart.series[curPoint.series.index + (down ? -1 : 1)];
if (!newSeries) {
return false;
}
// We have a new series in this direction, find the right point
// Weigh xDistance as counting much higher than Y distance
newPoint = getClosestPoint(curPoint, newSeries, 4);
if (!newPoint) {
return false;
}
// New series and point exists, but we might want to skip it
if (!newSeries.visible) {
// Skip the series
newPoint.highlight();
adjacentNewPoint = chart.highlightAdjacentSeries(down); // Try recurse
if (!adjacentNewPoint) {
// Recurse failed
curPoint.highlight();
return false;
}
// Recurse succeeded
return adjacentNewPoint;
}
// Highlight the new point or any first valid point back or forwards from it
newPoint.highlight();
return newPoint.series.highlightFirstValidPoint();
};
// Highlight the closest point vertically
H.Chart.prototype.highlightAdjacentPointVertical = function(down) {
var curPoint = this.highlightedPoint,
minDistance = Infinity,
bestPoint;
if (curPoint.plotX === undefined || curPoint.plotY === undefined) {
return false;
}
each(this.series, function(series) {
each(series.points, function(point) {
if (point.plotY === undefined || point.plotX === undefined ||
point === curPoint) {
return;
}
var yDistance = point.plotY - curPoint.plotY,
width = Math.abs(point.plotX - curPoint.plotX),
distance = Math.abs(yDistance) * Math.abs(yDistance) +
width * width * 4; // Weigh horizontal distance highly
// Reverse distance number if axis is reversed
if (series.yAxis.reversed) {
yDistance *= -1;
}
if (
yDistance < 0 && down || yDistance > 0 && !down || // Wrong dir
distance < 5 || // Points in same spot => infinite loop
isSkipPoint(point)
) {
return;
}
if (distance < minDistance) {
minDistance = distance;
bestPoint = point;
}
});
});
return bestPoint ? bestPoint.highlight() : false;
};
// Show the export menu and focus the first item (if exists)
H.Chart.prototype.showExportMenu = function() {
if (this.exportSVGElements && this.exportSVGElements[0]) {
this.exportSVGElements[0].element.onclick();
this.highlightExportItem(0);
}
};
// Highlight export menu item by index
H.Chart.prototype.highlightExportItem = function(ix) {
var listItem = this.exportDivElements && this.exportDivElements[ix],
curHighlighted =
this.exportDivElements &&
this.exportDivElements[this.highlightedExportItem];
if (
listItem &&
listItem.tagName === 'DIV' &&
!(listItem.children && listItem.children.length)
) {
if (listItem.focus) {
listItem.focus();
}
if (curHighlighted && curHighlighted.onmouseout) {
curHighlighted.onmouseout();
}
if (listItem.onmouseover) {
listItem.onmouseover();
}
this.highlightedExportItem = ix;
return true;
}
};
// Highlight range selector button by index
H.Chart.prototype.highlightRangeSelectorButton = function(ix) {
var buttons = this.rangeSelector.buttons;
// Deselect old
if (buttons[this.highlightedRangeSelectorItemIx]) {
buttons[this.highlightedRangeSelectorItemIx].setState(
this.oldRangeSelectorItemState || 0
);
}
// Select new
this.highlightedRangeSelectorItemIx = ix;
if (buttons[ix]) {
if (buttons[ix].element.focus) {
buttons[ix].element.focus();
}
this.oldRangeSelectorItemState = buttons[ix].state;
buttons[ix].setState(2);
return true;
}
return false;
};
// Highlight legend item by index
H.Chart.prototype.highlightLegendItem = function(ix) {
var items = this.legend.allItems;
if (items[this.highlightedLegendItemIx]) {
fireEvent(
items[this.highlightedLegendItemIx].legendGroup.element,
'mouseout'
);
}
this.highlightedLegendItemIx = ix;
if (items[ix]) {
if (items[ix].legendGroup.element.focus) {
items[ix].legendGroup.element.focus();
}
fireEvent(items[ix].legendGroup.element, 'mouseover');
return true;
}
return false;
};
// Hide export menu
H.Chart.prototype.hideExportMenu = function() {
var exportList = this.exportDivElements;
if (exportList) {
each(exportList, function(el) {
fireEvent(el, 'mouseleave');
});
if (
exportList[this.highlightedExportItem] &&
exportList[this.highlightedExportItem].onmouseout
) {
exportList[this.highlightedExportItem].onmouseout();
}
this.highlightedExportItem = 0;
this.renderTo.focus();
}
};
// Add keyboard navigation handling to chart
H.Chart.prototype.addKeyboardNavEvents = function() {
var chart = this;
// Abstraction layer for keyboard navigation. Keep a map of keyCodes to
// handler functions, and a next/prev move handler for tab order. The
// module's keyCode handlers determine when to move to another module.
// Validate holds a function to determine if there are prerequisites for
// this module to run that are not met. Init holds a function to run once
// before any keyCodes are interpreted. Terminate holds a function to run
// once before moving to next/prev module.
function KeyboardNavigationModule(options) {
this.id = options.id;
this.keyCodeMap = options.keyCodeMap;
this.move = options.move;
this.validate = options.validate;
this.init = options.init;
this.terminate = options.terminate;
}
KeyboardNavigationModule.prototype = {
// Find handler function(s) for key code in the keyCodeMap and run it.
run: function(e) {
var navModule = this,
keyCode = e.which || e.keyCode,
found = false,
handled = false;
each(this.keyCodeMap, function(codeSet) {
if (codeSet[0].indexOf(keyCode) > -1) {
found = true;
handled = codeSet[1].call(navModule, keyCode, e) === false ?
// If explicitly returning false, we haven't handled it
false :
true;
}
});
// Default tab handler, move to next/prev module
if (!found && keyCode === 9) {
handled = this.move(e.shiftKey ? -1 : 1);
}
return handled;
}
};
// Maintain abstraction between KeyboardNavigationModule and Highcharts.
// The chart object keeps track of a list of KeyboardNavigationModules that
// we move through.
function navModuleFactory(id, keyMap, options) {
return new KeyboardNavigationModule(merge({
keyCodeMap: keyMap,
// Move to next/prev valid module, or undefined if none, and init
// it. Returns true on success and false if there is no valid module
// to move to.
move: function(direction) {
if (this.terminate) {
this.terminate(direction);
}
chart.keyboardNavigationModuleIndex += direction;
var newModule = chart.keyboardNavigationModules[
chart.keyboardNavigationModuleIndex
];
if (newModule) {
if (newModule.validate && !newModule.validate()) {
return this.move(direction); // Invalid module
}
if (newModule.init) {
newModule.init(direction); // Valid module, init it
return true;
}
}
// No module
chart.keyboardNavigationModuleIndex = 0; // Reset counter
// Set focus to chart or exit anchor depending on direction
if (direction > 0) {
chart.tabExitAnchor.focus();
} else {
chart.renderTo.focus();
}
return false;
}
}, {
id: id
}, options));
}
// Route keydown events
function keydownHandler(ev) {
var e = ev || win.event,
curNavModule = chart.keyboardNavigationModules[
chart.keyboardNavigationModuleIndex
];
// If there is a navigation module for the current index, run it.
// Otherwise, we are outside of the chart in some direction.
if (curNavModule) {
if (curNavModule.run(e)) {
// Successfully handled this key event, stop default handling
e.preventDefault();
}
}
}
// List of the different keyboard handling modes we use depending on where
// we are in the chart. Each mode has a set of handling functions mapped to
// key codes. Each mode determines when to move to the next/prev mode.
chart.keyboardNavigationModules = [
// Entry point catching the first tab, allowing users to tab into points
// more intuitively.
navModuleFactory('entry', []),
// Points
// Prevents default and ignores failure regardless
navModuleFactory('points', [
// Left/Right
[
[37, 39],
function(keyCode) {
chart.highlightAdjacentPoint(keyCode === 39);
return true;
}
],
// Up/Down
[
[38, 40],
function(keyCode) {
var highlightMethod = chart.highlightedPoint &&
chart.highlightedPoint.series.keyboardMoveVertical ?
'highlightAdjacentPointVertical' :
'highlightAdjacentSeries';
chart[highlightMethod](keyCode !== 38);
return true;
}
],
// Enter/Spacebar
[
[13, 32],
function() {
if (chart.highlightedPoint) {
chart.highlightedPoint.firePointEvent('click');
}
}
]
], {
// Always start highlighting from scratch when entering this module
init: function() {
delete chart.highlightedPoint;
// Find first valid point to highlight
for (var i = 0; i < chart.series.length; ++i) {
for (var j = 0, len = chart.series[i].points &&
chart.series[i].points.length; j < len; ++j) {
if (!isSkipPoint(chart.series[i].points[j])) {
return chart.series[i].points[j].highlight();
}
}
}
},
// If leaving points, don't show tooltip anymore
terminate: function() {
if (chart.tooltip) {
chart.tooltip.hide(0);
}
delete chart.highlightedPoint;
}
}),
// Exporting
navModuleFactory('exporting', [
// Left/Up
[
[37, 38],
function() {
var i = chart.highlightedExportItem || 0,
reachedEnd = true;
// Try to highlight prev item in list. Highlighting e.g.
// separators will fail.
while (i--) {
if (chart.highlightExportItem(i)) {
reachedEnd = false;
break;
}
}
if (reachedEnd) {
chart.hideExportMenu();
return this.move(-1);
}
}
],
// Right/Down
[
[39, 40],
function() {
var highlightedExportItem = chart.highlightedExportItem || 0,
reachedEnd = true;
// Try to highlight next item in list. Highlighting e.g.
// separators will fail.
for (
var i = highlightedExportItem + 1; i < chart.exportDivElements.length;
++i
) {
if (chart.highlightExportItem(i)) {
reachedEnd = false;
break;
}
}
if (reachedEnd) {
chart.hideExportMenu();
return this.move(1); // Next module
}
}
],
// Enter/Spacebar
[
[13, 32],
function() {
fakeClickEvent(
chart.exportDivElements[chart.highlightedExportItem]
);
}
]
], {
// Only run exporting navigation if exporting support exists and is
// enabled on chart
validate: function() {
return (
chart.exportChart &&
!(
chart.options.exporting &&
chart.options.exporting.enabled === false
)
);
},
// Show export menu
init: function(direction) {
chart.highlightedPoint = null;
chart.showExportMenu();
// If coming back to export menu from other module, try to
// highlight last item in menu
if (direction < 0 && chart.exportDivElements) {
for (var i = chart.exportDivElements.length; i > -1; --i) {
if (chart.highlightExportItem(i)) {
break;
}
}
}
},
// Hide the menu
terminate: function() {
chart.hideExportMenu();
}
}),
// Map zoom
navModuleFactory('mapZoom', [
// Up/down/left/right
[
[38, 40, 37, 39],
function(keyCode) {
chart[keyCode === 38 || keyCode === 40 ? 'yAxis' : 'xAxis'][0]
.panStep(keyCode < 39 ? -1 : 1);
}
],
// Tabs
[
[9],
function(keyCode, e) {
var button;
// Deselect old
chart.mapNavButtons[chart.focusedMapNavButtonIx].setState(0);
if (
e.shiftKey && !chart.focusedMapNavButtonIx ||
!e.shiftKey && chart.focusedMapNavButtonIx
) { // trying to go somewhere we can't?
chart.mapZoom(); // Reset zoom
// Nowhere to go, go to prev/next module
return this.move(e.shiftKey ? -1 : 1);
}
chart.focusedMapNavButtonIx += e.shiftKey ? -1 : 1;
button = chart.mapNavButtons[chart.focusedMapNavButtonIx];
if (button.element.focus) {
button.element.focus();
}
button.setState(2);
}
],
// Enter/Spacebar
[
[13, 32],
function() {
fakeClickEvent(
chart.mapNavButtons[chart.focusedMapNavButtonIx].element
);
}
]
], {
// Only run this module if we have map zoom on the chart
validate: function() {
return (
chart.mapZoom &&
chart.mapNavButtons &&
chart.mapNavButtons.length === 2
);
},
// Make zoom buttons do their magic
init: function(direction) {
var zoomIn = chart.mapNavButtons[0],
zoomOut = chart.mapNavButtons[1],
initialButton = direction > 0 ? zoomIn : zoomOut;
each(chart.mapNavButtons, function(button, i) {
button.element.setAttribute('tabindex', -1);
button.element.setAttribute('role', 'button');
button.element.setAttribute(
'aria-label',
'Zoom ' + (i ? 'out' : '') + 'chart'
);
});
if (initialButton.element.focus) {
initialButton.element.focus();
}
initialButton.setState(2);
chart.focusedMapNavButtonIx = direction > 0 ? 0 : 1;
}
}),
// Highstock range selector (minus input boxes)
navModuleFactory('rangeSelector', [
// Left/Right/Up/Down
[
[37, 39, 38, 40],
function(keyCode) {
var direction = (keyCode === 37 || keyCode === 38) ? -1 : 1;
// Try to highlight next/prev button
if (!chart.highlightRangeSelectorButton(
chart.highlightedRangeSelectorItemIx + direction
)) {
return this.move(direction);
}
}
],
// Enter/Spacebar
[
[13, 32],
function() {
// Don't allow click if button used to be disabled
if (chart.oldRangeSelectorItemState !== 3) {
fakeClickEvent(
chart.rangeSelector.buttons[
chart.highlightedRangeSelectorItemIx
].element
);
}
}
]
], {
// Only run this module if we have range selector
validate: function() {
return (
chart.rangeSelector &&
chart.rangeSelector.buttons &&
chart.rangeSelector.buttons.length
);
},
// Make elements focusable and accessible
init: function(direction) {
each(chart.rangeSelector.buttons, function(button) {
button.element.setAttribute('tabindex', '-1');
button.element.setAttribute('role', 'button');
button.element.setAttribute(
'aria-label',
'Select range ' + (button.text && button.text.textStr)
);
});
// Focus first/last button
chart.highlightRangeSelectorButton(
direction > 0 ? 0 : chart.rangeSelector.buttons.length - 1
);
}
}),
// Highstock range selector, input boxes
navModuleFactory('rangeSelectorInput', [
// Tab/Up/Down
[
[9, 38, 40],
function(keyCode, e) {
var direction =
(keyCode === 9 && e.shiftKey || keyCode === 38) ? -1 : 1,
newIx = chart.highlightedInputRangeIx =
chart.highlightedInputRangeIx + direction;
// Try to highlight next/prev item in list.
if (newIx > 1 || newIx < 0) { // Out of range
return this.move(direction);
}
chart.rangeSelector[newIx ? 'maxInput' : 'minInput'].focus();
}
]
], {
// Only run if we have range selector with input boxes
validate: function() {
var inputVisible = (
chart.rangeSelector &&
chart.rangeSelector.inputGroup &&
chart.rangeSelector.inputGroup.element
.getAttribute('visibility') !== 'hidden'
);
return (
inputVisible &&
chart.options.rangeSelector.inputEnabled !== false &&
chart.rangeSelector.minInput &&
chart.rangeSelector.maxInput
);
},
// Highlight first/last input box
init: function(direction) {
chart.highlightedInputRangeIx = direction > 0 ? 0 : 1;
chart.rangeSelector[
chart.highlightedInputRangeIx ? 'maxInput' : 'minInput'
].focus();
}
}),
// Legend navigation
navModuleFactory('legend', [
// Left/Right/Up/Down
[
[37, 39, 38, 40],
function(keyCode) {
var direction = (keyCode === 37 || keyCode === 38) ? -1 : 1;
// Try to highlight next/prev legend item
if (!chart.highlightLegendItem(
chart.highlightedLegendItemIx + direction
)) {
return this.move(direction);
}
}
],
// Enter/Spacebar
[
[13, 32],
function() {
fakeClickEvent(
chart.legend.allItems[
chart.highlightedLegendItemIx
].legendItem.element.parentNode
);
}
]
], {
// Only run this module if we have at least one legend - wait for
// it - item. Don't run if the legend is populated by a colorAxis.
// Don't run if legend navigation is disabled.
validate: function() {
return chart.legend && chart.legend.allItems &&
!(chart.colorAxis && chart.colorAxis.length) &&
(chart.options.legend &&
chart.options.legend.keyboardNavigation &&
chart.options.legend.keyboardNavigation.enabled) !== false;
},
// Make elements focusable and accessible
init: function(direction) {
each(chart.legend.allItems, function(item) {
item.legendGroup.element.setAttribute('tabindex', '-1');
item.legendGroup.element.setAttribute('role', 'button');
item.legendGroup.element.setAttribute(
'aria-label',
'Toggle visibility of series ' + item.name
);
});
// Focus first/last item
chart.highlightLegendItem(
direction > 0 ? 0 : chart.legend.allItems.length - 1
);
}
})
];
// Init nav module index. We start at the first module, and as the user
// navigates through the chart the index will increase to use different
// handler modules.
chart.keyboardNavigationModuleIndex = 0;
// Make chart reachable by tab
if (
chart.container.hasAttribute &&
!chart.container.hasAttribute('tabIndex')
) {
chart.container.setAttribute('tabindex', '0');
}
// Add tab exit anchor
// We use this to move focus out of chart whenever we want, by setting focus
// to this and not preventing the default tab action.
if (!chart.tabExitAnchor) {
chart.tabExitAnchor = doc.createElement('div');
// Not reachable by user
chart.tabExitAnchor.setAttribute('tabindex', '-1');
merge(true, chart.tabExitAnchor.style, hiddenStyle);
chart.renderTo.appendChild(chart.tabExitAnchor);
}
// Handle keyboard events
addEvent(chart.renderTo, 'keydown', keydownHandler);
addEvent(chart, 'destroy', function() {
removeEvent(chart.renderTo, 'keydown', keydownHandler);
});
};
// Add screen reader region to chart.
// tableId is the HTML id of the table to focus when clicking the table anchor
// in the screen reader region.
H.Chart.prototype.addScreenReaderRegion = function(id, tableId) {
var chart = this,
series = chart.series,
options = chart.options,
a11yOptions = options.accessibility,
hiddenSection = chart.screenReaderRegion = doc.createElement('div'),
tableShortcut = doc.createElement('h4'),
tableShortcutAnchor = doc.createElement('a'),
chartHeading = doc.createElement('h4'),
chartTypes = chart.types || [],
// Build axis info - but not for pies and maps. Consider not adding for
// certain other types as well (funnel, pyramid?)
axesDesc = (
chartTypes.length === 1 && chartTypes[0] === 'pie' ||
chartTypes[0] === 'map'
) && {} || chart.getAxesDescription(),
chartTypeInfo = series[0] && typeToSeriesMap[series[0].type] ||
typeToSeriesMap['default']; // eslint-disable-line dot-notation
hiddenSection.setAttribute('id', id);
hiddenSection.setAttribute('role', 'region');
hiddenSection.setAttribute(
'aria-label',
'Chart screen reader information.'
);
hiddenSection.innerHTML =
a11yOptions.screenReaderSectionFormatter &&
a11yOptions.screenReaderSectionFormatter(chart) ||
'Use regions/landmarks to skip ahead to chart' +
(series.length > 1 ? ' and navigate between data series' : '') +
'.
' +
(options.title.text ? htmlencode(options.title.text) : 'Chart') +
(
options.subtitle && options.subtitle.text ?
'. ' + htmlencode(options.subtitle.text) :
''
) +
'
Long description.
' +
(options.chart.description || 'No description available.') +
'
Structure.
Chart type: ' +
(options.chart.typeDescription || chart.getTypeDescription()) +
'
' +
(
series.length === 1 ?
(
'' + chartTypeInfo[0] + ' with ' +
series[0].points.length + ' ' +
(
series[0].points.length === 1 ?
chartTypeInfo[1] :
chartTypeInfo[2]
) +
'.
'
) : ''
) +
(axesDesc.xAxis ? ('' + axesDesc.xAxis + '
') : '') +
(axesDesc.yAxis ? ('' + axesDesc.yAxis + '
') : '');
// Add shortcut to data table if export-data is loaded
if (chart.getCSV) {
tableShortcutAnchor.innerHTML = 'View as data table.';
tableShortcutAnchor.href = '#' + tableId;
// Make this unreachable by user tabbing
tableShortcutAnchor.setAttribute('tabindex', '-1');
tableShortcutAnchor.onclick =
a11yOptions.onTableAnchorClick || function() {
chart.viewData();
doc.getElementById(tableId).focus();
};
tableShortcut.appendChild(tableShortcutAnchor);
hiddenSection.appendChild(tableShortcut);
}
// Note: JAWS seems to refuse to read aria-label on the container, so add an
// h4 element as title for the chart.
chartHeading.innerHTML = 'Chart graphic.';
chart.renderTo.insertBefore(chartHeading, chart.renderTo.firstChild);
chart.renderTo.insertBefore(hiddenSection, chart.renderTo.firstChild);
// Hide the section and the chart heading
merge(true, chartHeading.style, hiddenStyle);
merge(true, hiddenSection.style, hiddenStyle);
};
// Make chart container accessible, and wrap table functionality
H.Chart.prototype.callbacks.push(function(chart) {
var options = chart.options,
a11yOptions = options.accessibility;
if (!a11yOptions.enabled) {
return;
}
var titleElement = doc.createElementNS(
'http://www.w3.org/2000/svg',
'title'
),
exportGroupElement = doc.createElementNS(
'http://www.w3.org/2000/svg',
'g'
),
descElement = chart.container.getElementsByTagName('desc')[0],
textElements = chart.container.getElementsByTagName('text'),
titleId = 'highcharts-title-' + chart.index,
tableId = 'highcharts-data-table-' + chart.index,
hiddenSectionId = 'highcharts-information-region-' + chart.index,
chartTitle = options.title.text || 'Chart',
oldColumnHeaderFormatter = (
options.exporting &&
options.exporting.csv &&
options.exporting.csv.columnHeaderFormatter
),
topLevelColumns = [];
// Add SVG title/desc tags
titleElement.textContent = htmlencode(chartTitle);
titleElement.id = titleId;
descElement.parentNode.insertBefore(titleElement, descElement);
chart.renderTo.setAttribute('role', 'region');
chart.renderTo.setAttribute(
'aria-label',
'Interactive chart. ' + chartTitle +
'. Use up and down arrows to navigate with most screen readers.'
);
// Set screen reader properties on export menu
if (
chart.exportSVGElements &&
chart.exportSVGElements[0] &&
chart.exportSVGElements[0].element
) {
var oldExportCallback = chart.exportSVGElements[0].element.onclick,
parent = chart.exportSVGElements[0].element.parentNode;
chart.exportSVGElements[0].element.onclick = function() {
oldExportCallback.apply(
this,
Array.prototype.slice.call(arguments)
);
chart.addAccessibleContextMenuAttribs();
chart.highlightExportItem(0);
};
chart.exportSVGElements[0].element.setAttribute('role', 'button');
chart.exportSVGElements[0].element.setAttribute(
'aria-label',
'View export menu'
);
exportGroupElement.appendChild(chart.exportSVGElements[0].element);
exportGroupElement.setAttribute('role', 'region');
exportGroupElement.setAttribute('aria-label', 'Chart export menu');
parent.appendChild(exportGroupElement);
}
// Set screen reader properties on input boxes for range selector. We need
// to do this regardless of whether or not these are visible, as they are
// by default part of the page's tabindex unless we set them to -1.
if (chart.rangeSelector) {
each(['minInput', 'maxInput'], function(key, i) {
if (chart.rangeSelector[key]) {
chart.rangeSelector[key].setAttribute('tabindex', '-1');
chart.rangeSelector[key].setAttribute('role', 'textbox');
chart.rangeSelector[key].setAttribute(
'aria-label',
'Select ' + (i ? 'end' : 'start') + ' date.'
);
}
});
}
// Hide text elements from screen readers
each(textElements, function(el) {
el.setAttribute('aria-hidden', 'true');
});
// Add top-secret screen reader region
chart.addScreenReaderRegion(hiddenSectionId, tableId);
// Enable keyboard navigation
if (a11yOptions.keyboardNavigation.enabled) {
chart.addKeyboardNavEvents();
}
/* Wrap table functionality from export-data */
// Keep track of columns
merge(true, options.exporting, {
csv: {
columnHeaderFormatter: function(item, key, keyLength) {
if (!item) {
return 'Category';
}
if (item instanceof H.Axis) {
return (item.options.title && item.options.title.text) ||
(item.isDatetimeAxis ? 'DateTime' : 'Category');
}
var prevCol = topLevelColumns[topLevelColumns.length - 1];
if (keyLength > 1) {
// We need multiple levels of column headers
// Populate a list of column headers to add in addition to
// the ones added by export-data
if ((prevCol && prevCol.text) !== item.name) {
topLevelColumns.push({
text: item.name,
span: keyLength
});
}
}
if (oldColumnHeaderFormatter) {
return oldColumnHeaderFormatter.call(
this,
item,
key,
keyLength
);
}
return keyLength > 1 ? key : item.name;
}
}
});
// Add ID and title/caption to table HTML
H.wrap(chart, 'getTable', function(proceed) {
return proceed.apply(this, Array.prototype.slice.call(arguments, 1))
.replace(
'',
'' + chartTitle + ''
);
});
// Add accessibility attributes and top level columns
H.wrap(chart, 'viewData', function(proceed) {
if (!this.dataTableDiv) {
proceed.apply(this, Array.prototype.slice.call(arguments, 1));
var table = doc.getElementById(tableId),
head = table.getElementsByTagName('thead')[0],
body = table.getElementsByTagName('tbody')[0],
firstRow = head.firstChild.children,
columnHeaderRow = ' | ',
cell,
newCell;
// Make table focusable by script
table.setAttribute('tabindex', '-1');
// Create row headers
each(body.children, function(el) {
cell = el.firstChild;
newCell = doc.createElement('th');
newCell.setAttribute('scope', 'row');
newCell.innerHTML = cell.innerHTML;
cell.parentNode.replaceChild(newCell, cell);
});
// Set scope for column headers
each(firstRow, function(el) {
if (el.tagName === 'TH') {
el.setAttribute('scope', 'col');
}
});
// Add top level columns
if (topLevelColumns.length) {
each(topLevelColumns, function(col) {
columnHeaderRow += '' + col.text + ' | ';
});
head.insertAdjacentHTML('afterbegin', columnHeaderRow);
}
}
});
});
}(Highcharts));
}));
|---|